The respondents were charged with conspiracy to import heroin.
At trial, the Crown led evidence of the importation of cocaine.
The trial judge instructed the jury that they could convict if satisfied the respondents conspired to import any narcotic, leading to convictions.
The Court of Appeal set aside the convictions and ordered a new trial.
The Supreme Court of Canada dismissed the Crown's appeal, holding that the Crown must prove the offence as particularized in the charge.
The Court also refused to allow the Crown to amend the charge, as doing so retroactively would be unfair and prejudicial to the respondents.
